Spark plug indexing

On a stock car, probably not much. Less than a single horsepower I’d bet, but good for the guys who are stuck in the classes that "must" utilize stock parts.

I have in the past cut back the "spark plug electrode ground" located at the top of the plug on this pick until it was centered over the electrode.
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It's said to more efficiently distribute spark, resulting in better flame propaganda and over all efficiency. It's an old hot rod trick, but I doubt anyone’s actually ever dyno'd it?